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Extent of coastal habitats

Why we monitor the extent of coastal habitats

Photograph of seagrass in Moonlight Bay, Whaingaroa Harbour (Raglan)

Caption: Seagrass in Moonlight Bay, Whaingaroa (Raglan) Harbour.

This indicator is based on an estimate of the spatial extent and distribution of different intertidal vegetated habitats in selected estuaries within the Waikato region.

For practical purposes the dominant vegetation type is used to categorise four communities; mangrove, salt marsh, seagrass and invasive plants. In reality these communities may be mixed and it is the changes in proportions of plant species forming these mixtures in response to changing environmental conditions that advise estuary management.

Examples of individual environmental drivers may be climate change, a direct result of human activity within an estuary or activities within an estuary catchment. Understanding the impact of environmental drivers on plant communities within an estuary enables targeted policies and management practices.

The information for this indicator is based on interpretation of aerial photographs and field surveys. Currently this indicator covers 19 estuaries in the Waikato; 15 on the East Coast (including the southern Firth of Thames) and four on the West Coast.

The current data for the estuaries on the East Coast was collected from Waikato Regional Aerial Photographs (WRAPS) taken in 2007 and 2012, and the data for West Coast estuaries from WRAPS taken in 2012.

Estuaries have been identified as one of the coastal areas within the region most at risk from human activities. Many different types of communities are found in and around estuaries, including coastal forest, salt meadows and salt marshes, mangroves, seagrass beds, sand and mud flats, rocky reefs and shallow open water areas. Protecting the diversity of habitats provided by these plant communities is an important factor in maintaining the diverse roles of the region's estuarine ecosystems.

Waikato Regional Council has developed a Regional Estuary Monitoring Programme to provide a more comprehensive understanding of the region’s estuarine environments and the threats they face. Monitoring changes in extent, distribution and type of intertidal estuarine habitats is an aspect of this programme. Waikato Regional Council uses this information to identify policy responses and make consent decisions so that we can avoid or remedy adverse affects on estuarine environments.
Find out about Waikato Regional Council’s policies relating to natural character, habitat and coastal processes in the section 3 of the Regional Coastal Plan.

What's happening?

Currently, this indicator looks at intertidal vegetated habitats in 19 estuaries in the Waikato region: 15 estuaries on the East Coast and 4 on the West Coast.

>> Find out more about these data and trends

More information

When this indicator is updated

This indicator is updated every five years, with the next update scheduled for 2021.

Contact at Waikato Regional Council

Coastal Scientist - Science and Strategy Directorate

Updated 1 July 2016